Support Needed With Fixing PC Internal Display

ISSUE: I previously improved the fan performance in my PC by physically cleaning the fan. But it now displays a black screen due to suspected hardware issues. It works completely fine when connected to external monitor via HDMI to HDMI cable. This needs to be fixed so that private PC internal screen can also display in addition to extending and duplicating screens with my external monitor. PC MANUFACTURER, MODEL and OS dynabook P1-E9MJ-BL, Windows 11 Pro SKILLS NEEDED: -Proficiency in PC hardware diagnosis and repair -Proficiency in PC parts replacement -Fluent in both Japanese and English languages -Live in Tokyo / Yokohama Metropolitan Area -Compliant with Freelancer.com codes of conduct and rules SUPPORT NEEDED: I have various tools for PC repair in my toolbox and some knowledge and experience in fixing my PC hardware. I will also explain the troubleshooting I have previously done. Please help me to fix the problem outside of my main job working hours. Specifically I would like instructions for further troubleshooting. Also if spare parts are needed, please help me to purchase the parts. Afterwards, I would like a consolidated report in electronic format that describes how the problem is fixed.